Break the chocolate into small pieces and add to a heatproof bowl. Add 3 tbsp butter. Add a little boiling water to a saucepan and heat until simmering. Suspend the bowl over the simmering water, but do not allow the base of the bowl to touch the water. Heat the chocolate, stirring regularly, until completely melted. Then put in a piping bag.

Outline melted snowman shape then flood it with the warm chocolate. Let it cool slightly. Then roll the marshmallows in chocolate and pop right on top of your cookie as the head. Now let it harden completely.